.math-title {
    line-height: 1;
    margin: 0 0 10px 0;
}
.math-menu {
    position: relative;
    list-style: none;
    padding: 0;
    margin: 0;
    width: 420px;
    line-height: 1;
    background-image: -webkit-linear-gradient(top,#F5F5F5,#EFEFEF);
    padding: 2px 5px;
    border: 1px solid #ccc;
    box-sizing: border-box;
}
.math-menu .math-item {
    display: inline-block;
    cursor: pointer;
    padding: 2px 0;
    margin: 0 5px 0 0;
    border: 1px solid transparent;
    border-radius: 3px;
    box-sizing: content-box;
}
.math-menu .math-item:last-child {
    margin-right: 0;
}
.math-menu .math-item:hover {
    border-color: #cfcfcf;
}
.math-code {
    background: url('./codes.png') no-repeat; 
}
.math-code-list {
    list-style: none;
    padding: 0;
    margin: 0;
    width: 320px;
    background: #fff;
    cursor: default;
    padding: 5px;
    border: 1px solid #cfcfcf;
    box-sizing: border-box;
}
.math-code-list .math-code-item {
    display: inline-block;
    cursor: pointer;
    padding: 2px;
    margin: 0;
    border: 1px solid transparent;
}
.math-code-list .math-code-item:hover {
    background-color: #f6f6f6;
    border-color: #42a5f5;
}
.math-code-list .math-code-item .math-code {
    display: block;
}

.math-text {
    width: 100%;
    height: 100px;
    outline: none;
    resize: vertical;
    padding: 5px;
    border: 1px solid #cfcfcf;
    border-top: none;
    box-sizing: border-box;
}

.math-hint {
    position: absolute;
    left: 0; top: 50%;
    transform: translateY(-50%);
    font-size: 12px;
    border-radius: 2px;
    padding: 5px;
    color: #42a5f5;
    cursor: pointer;
    text-decoration: none;
}
.math-hint:hover {
    background: #f6f6f6;
}

.math-preview {
    height: 100px;
    line-height: 100px;
    text-align: center;
    padding: 5px;
    border: 1px dashed #cfcfcf;
    box-sizing: border-box;
}
.math-preview>img {
    max-width: 100%;
    max-height: 100%;
}